From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A8412EB5C9; Mon, 13 Oct 2025 08:23:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760343793; cv=none; b=cZucVFEGKVFM7pOl25amp6ziWEle+rSnIlrsyfSqMFU8Pqy8v1gd8YshaQOP6Rl10l6/pX54DLbhufOWY0vIeynATbPFytghJo2AjvXosWShuzGpqpj898dvNYfuN4ahaXnPJrsYLP+L51XMRWbKTKnVT+zfawWA05NZNDc64V8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760343793; c=relaxed/simple; bh=1kR31gbBKnUscwS6ZTjsnygKJs8ivj+9YtUWNXRZP3Q=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=ZbFFeE+sldQUBKqyAXmWv7iXh8btwxFtf3SS556QYE9/u4F5uDilfERc4pe86ImffFiTNbGCD+DJ8OKFrXyIiGSIgZCsQPjkZQlvBKbDhRvj2G2m1queIuaV5wmPk3W6GjaHIp1neVeT8gzJzTAdfjAQmZtqPzYxvVC0Ux4K1qM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=O2nd+b5Z; arc=none smtp.client-ip=95.215.58.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="O2nd+b5Z" Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1760343786; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vvAwE+mYlFFTAsj2rEKkqTesljDavewgCpk7RarO+os=; b=O2nd+b5ZQqqRTbpp7mYz1uktv8h7XNclbxxqpyGymBYBngnMHmyYjuFOAgkEMdPm8i0pzh P+JyicDM6y7IsHrVTw1R7I7HNePuy38/7pTu2zdYsYE3XVc5zlyKySaLNJ/bZIVwE2lNnc qtcTON8QsOaizF3zblxb4jSQlMXxQAE= Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.700.81\)) Subject: Re: [PATCH v2 1/2] crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Thorsten Blum In-Reply-To: Date: Mon, 13 Oct 2025 10:23:01 +0200 Cc: David Howells , Ignat Korchagin , Herbert Xu , "David S. Miller" , Vivek Goyal , stable@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <4AF8BE0F-D400-4020-A8F6-EF61A797A24E@linux.dev> References: <20251012203841.60230-1-thorsten.blum@linux.dev> To: Lukas Wunner X-Migadu-Flow: FLOW_OUT On 13. Oct 2025, at 08:24, Lukas Wunner wrote: > On Sun, Oct 12, 2025 at 10:38:40PM +0200, Thorsten Blum wrote: >> +++ b/crypto/asymmetric_keys/asymmetric_type.c >> @@ -141,12 +142,14 @@ struct asymmetric_key_id = *asymmetric_key_generate_id(const void *val_1, >> size_t len_2) >> { >> struct asymmetric_key_id *kid; >> + size_t len; >>=20 >> - kid =3D kmalloc(sizeof(struct asymmetric_key_id) + len_1 + = len_2, >> - GFP_KERNEL); >> + if (check_add_overflow(len_1, len_2, &len)) >> + return ERR_PTR(-EOVERFLOW); >> + kid =3D kmalloc(struct_size(kid, data, len), GFP_KERNEL); >=20 > This will add (at least) 2 bytes to len (namely the size of struct > asymmetric_key_id)) and may cause an overflow (even if len_1 + len_2 > did not overflow). Could you explain which part adds "(at least) 2 bytes to len"? Thanks, Thorsten